FORT LAUDERDALE, Florida — Before “The Love Boat” set sail on its 10-year TV voyage, taking a cruise vacation was a luxury reserved for the wealthy few. Even actor Gavin MacLeod admits he had never stayed aboard a cruise ship until he was cast as the captain in the hit ABC series.

“[O]ur show has been recognized all over the country, all over the world as being the motor, the genesis that started cruising for the masses,” Mr. MacLeod said. “Before we did the pilot, I didn’t even know there was an elevator on a ship.”

Mr. MacLeod, who starred as Capt. Merrill Stubing, reunited with the other five regular cast members last week here as part of a celebration timed to coincide with the North American launch of the Regal Princess, the newest ship in the Princess Cruises line.

“The Love Boat” ran from 1977 to 1987 as part of Aaron Spelling Productions’ string of television hits, which included “Fantasy Island” and “Charlie’s Angels.” As Mr. MacLeod told cruisegoers at a question-and-answer session aboard the Regal Princess, however, critics predicted the show would flounder.

“They said we were going to sink like the Titanic, we weren’t going to last. They called it ‘mindless television.’ ‘You can’t do three different kinds of stories, and why on a boat? Come on,’” Mr. MacLeod said. “None of them liked it. But after we were on like the first or second week, the numbers went through the roof. In the wintertime, it was sensational when it was freezing all over the country.

The show, which continues to draw viewers in syndication in the U.S. and abroad, also is credited with introducing the cruising industry to the vacation-going public. In 1970, just 500,000 vacationers reported having taken a cruise that year; by 2009, the number had ballooned to 14.3 million, making cruises the fastest-growing segment of the U.S. travel industry, according to Cruise Lines International Association.

The launch of the Regal Princess marks the 50th anniversary of Princess Cruises, which has grown to 18 ships from its start in 1965 with a single ship traveling to Mexico. “The Love Boat” stars commemorated the anniversary by christening the Regal Princess with 50 champagne bottles.

Fred Grandy, who played chief purser Burl “Gopher” Smith, said some scenes were filmed on a soundstage at 20th Century Fox, but producers Aaron Spelling and Doug Cramer insisted that the ship — the Pacific Princess — actually travel to its locations.

“Aaron Spelling and Doug Cramer figured out very well that the star of the show was not us, the star was the ship and some of the guest stars. So it was critically important that we actually got on the ship and went places,” said Mr. Grandy, who later served four terms in Congress.

“Cruising was a whole different deal in the late ‘70s. It was something you could do if you were fabulously wealthy or about to die — or both,” said Mr. Grandy.

Even so, part of the show’s appeal was the chemistry among cast members, who joked and poked fun at each other throughout the onstage interview. Ted Lange, who played ship’s bartender Isaac Washington, drew some ribbing after declaring that he got his job without an audition, unlike the others.

Mr. Lange said the only question the producers asked him before casting him was, “Do you get seasick?” He said he didn’t, but then wound up getting seasick on a cruise to Alaska.

Lauren Tewes, who played cruise director Julie McCoy, said the guest star who impressed her the most was Vincent Price because “he was the first real gentleman I ever met.”

There were some lucky accidents that led to the casting of the six actors. Mr. MacLeod said the producers originally wanted Ted Knight, his former costar on “The Mary Tyler Moore Show,” to play the captain, but the late Mr. Knight already was working on another series.

Mr. Lange and Jill Whelan, who played Capt. Stubing’s daughter, Vicki, were known to Mr. Spelling because they previously had worked on other Spelling TV shows.

Bernie Kopell, who played the ship’s doctor, Adam Bricker, said he credited his casting in part to the nautical jacket he wore to the audition.

“Some actor came up to me, and I had a nautical jacket on, and he didn’t know what I was there for, and said, ‘That jacket is so right. I’m auditioning for the role of the doctor. Would you let me use that jacket?’ ” Mr. Kopell said. “And you’re supposed to be generous and all that, and I said, ‘I feel a little guilty about saying this, but no.’ “

Cast members said they remain friends and occasionally work on projects together. Both Mr. Kopell and Ms. Whelan have appeared in plays written by Mr. Lange, a prolific playwright.

“We became essentially a family. As magnificent as the Pacific Princess was — and as Fred said, the Pacific Princess was the star of the show — we essentially loved each other so much that our camaraderie became very important,” Mr. Kopell said. “We liked each other, we loved each other, we’ve been dear, dear friends for years and years.”

Princess Cruises included a few unique touches for the Regal Princess, such as the foghorn, which plays the first few notes of “The Love Boat” theme song upon departure.

Admittedly, “The Love Boat” will never be confused with “Masterpiece Theatre,” but Mr. Grandy says he thinks he knows what makes the show so memorable.

“Don’t forget, this was before there were things like the Travel Channel and the kinds of shows you can see now on a variety of cable networks. This was the way a lot of people traveled back when there were three networks,” Mr. Grandy said.

“I’m from Iowa. You couldn’t get out of Iowa between the end of November and the end of February because of the snow, but you could sit in front of your television set with your family on Saturday night and watch 'The Love Boat,' ” he said. “And that’s a phenomenon I don’t think we’ll ever repeat.”